A voltage source converter (VSC) can be used as a sinusoidal voltage source with controllable amplitude and angle. When placed in series with a transmission line, this source can control the flow of active and/or reactive power in the line thereby operating as a series compensator Note that in the mode of active power controller a separate DC source of energy i.e. battery is required. With this in mind, an EMTP model of the SSSC was developed for simulation studies. A single-phase model is presented here for reasons of simplicity and reducing simulation time, however a three-phase model is easy to construct from the principles outlined here. Details of the model are provided along with preliminary tests for the controller design.